UN war crimes judges in The Hague sentenced Karadzic to 40 years in prison after finding him guilty of the 1995 Srebrenica massacre and other atrocities during the Bosnian conflict.

"This judgment sends a strong signal to all who are in positions of responsibility that they will be held accountable for their actions and shows that fugitives cannot outrun the international community's collective resolve to make sure they face justice according to the law," Ban said in a statement from UN spokesman Farhan Haq.

"This is a historic day for the people of the region and beyond, as well as for the international criminal justice."

The verdict was handed down by the International Criminal Tribunal for the Former Yugoslavia after a marathon trial that probed Karadzic's role in the 1992-95 conflict that claimed more than 100,000 lives.

The 70-year-old was found guilty of genocide for the massacre of 8,000 Muslim men and boys in the town of Srebrenica in eastern Bosnia, and nine other charges of murder, persecution and hostage-taking.